Anaphylactoid phototoxic reactions – prevention
Avoidance of light exposure has formed the mainstay of erythropoietic protoporphyria management. This involves complete light and sun avoidance and the use of light-protective clothing including wide brimmed hats and gloves when exposure is unavoidable. Certain artificial lighting must also avoided by some patients, particularly modern energy saver globes and fluorescent tube lighting.
The majority of patients adapt their lives to minimise the risk associated with light and sun exposure. The avoidance of risk often forces patients to adopt careers where they can work during the night or away from any light exposure.
“Shadow hopping” or “shade hopping” is a commonly described phenomenon where patients will adapt their habits and movements such that they can minimise exposure.
Amber filters on windows (at home, work/school and on vehicles) provide some protective efficacy for some patients as they block many of the wavelengths of light responsible for phototoxicity. Filters are also recommended for use on operating lamps in theatre for EPP patients where a procedure – such as liver transplant – is being performed.
Most sunscreens (“sunblocks”) are totally ineffective for EPP as they do not block the wavelengths of visible light responsible for phototoxic reactions. Specially formulated visible-light sunscreens have been reported as partially effective, however their cosmetic effects have been reported as undesirable by patients.
As blue light also penetrates the eye, EPP patients are advised to wear sunglasses when going outside.
Several therapies have been proposed to help increase EPP patients’ tolerance to light and prevent phototoxic reactions. More information on treatment options should be sought from a qualified medical professional. See the homepage to view an interactive map of EPP expert centres.
Phototoxic reactions – alleviation
Following a phototoxic reaction patients seek to avoid further light and sun exposure and provide symptomatic relief to the skin. Most often this involves cold compresses (wet towels, ice) or submerging skin into extremely hot water. Patients will avoid any further stimuli on their skin – particularly further light exposure, but also sources of heat, wind or pressure. Self-medication is common to deal with insomnia, with adult patients resorting to sleeping pills and/or alcohol (despite the risks posed to the liver).
In severe episodes of phototoxicity patients may need to be hospitalised.
Prevention and management of hepatic symptoms, liver disease and gallstones
Annual examination of liver function is an essential part of EPP management to monitor and detect potential complications. Vaccination against hepatitis A and B is recommended, along with the avoidance of behaviour which poses a risk to the liver, particularly excessive alcohol consumption.
Liver disease is often associated with rising protoporphyrin levels in blood and increased photosensitivity. If an EPP patient feels that he or she is becoming less tolerant to light, then liver function tests are generally recommended.
Liver transplantation is often the only option for patients with liver failure. Over 40 liver transplantations have been reported in EPP patients in medical literature, mostly in adults but also in teenagers and even in children. Liver transplant does not cure EPP. As a result, patients continue to experience phototoxic reactions and the transplanted liver may be further damaged by PPIX molecules. Bone marrow transplant is curative for EPP and has been performed as an option for patients undergoing liver transplantation. Several mechanisms for avoiding or slowing terminal liver failure have been suggested in the literature, including exchange blood transfusion and plasmapheresis and are often used pre-transplant.
Surgery is considered appropriate for patients with symptomatic gallstones.
Management of systemic symptoms
Despite regular reports of anaemia in EPP patients, oral supplementation with iron has been generally found to be ineffective and may actually increase protoporphyrin levels and/or exacerbate phototoxic symptoms. Iron should only be prescribed if there is additional evidence of iron deficiency such as a markedly reduced serum ferritin level, and other symptoms arising from anaemia.
Vitamin D deficiency can be treated in EPP with oral supplementation. While there is discussion in the literature of the amount of vitamin D required, 5000 IU of oral vitamin D daily have been recommended for EPP patients.
EPP during pregnancy and menstruation
Various studies have highlighted reports from erythropoietic protoporphyria patients that their phototoxic symptoms were improved during pregnancy – especially during the second half of pregnancy – and during lactation. Occasionally pregnant EPP patients report an increase in phototoxicity. The mechanism of action for these changes is not well understood, however it has been speculated that an increase in alpha-melanocyte-stimulating hormone production during pregnancy, in addition to the reported decrease in red blood cell PPIX levels, may be responsible for lessened symptoms.
No major birth defects have been noted in children born to EPP patients. There is considered to be a 2-3% risk of children inheriting the disorder from a symptomatic parent with ferrochelatase mutations. In the X-linked dominant form of EPP, fathers with the disease pass the gene on only to their daughters and not to their sons. For mothers with this type of EPP, children have a 50% chance of inheriting the gene with the mutation.
Regardless of a formal diagnosis, once EPP patients recognise light as the cause of their symptoms they will forcibly deprive themselves of light exposure to avoid phototoxicity and the fear of possible reactions.
The biological effects of longer term light starvation in man is poorly understood and not well researched, except for the area of vitamin D. Some parallels can be drawn to the percentage of people living in Nordic countries suffering from Seasonal Affective Disorder (SAD), making them prone to depressive mood disorders. EPP has certain traits resembling SAD but has a far more severe impact on lives of patients.